Recording tape cartridge

ABSTRACT

In the cartridge, the opening is formed diagonally to an arrow A direction by cutting away a corner portion at a drive device loading side, and the opening faces both the arrow A direction and an arrow B direction. A leader pin and a magnetic tape are drawn out along the minimal length path from the opening. A door, which is formed in a circular arc shape in plan view, is guided (to suppress looseness) by case screw bosses, protrusion portions and a guide surface while the door rotates to turn at an outer side of a pin stand and the reel without deviating from a movement path along the form of curvature of the door, and thus the opening is opened/closed.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a recording tape cartridge whichrotatably accommodates a single reel onto which a recording tape such asa magnetic tape or the like is wound.

2. Description of the Related Art

Recording tapes such as magnetic tapes and the like are used as externalrecording media for computers and the like. Recording tape cartridgesthat accommodate a single reel on which a recording tape is wound takeup little space when stored and can record large amounts of information,and are employed as such recording tapes.

An opening aperture is formed in a case of such a recording tapecartridge. The recording tape is drawn out through this opening, andwound around a drive device side winding reel. Accordingly, there havebeen various schemes in the prior art for preventing dust and the likefrom ingressing through the opening aperture and adhering to therecording tape.

In a recording tape cartridge 100 shown in FIG. 7, an opening 104 isformed in a side wall 102A of a case 102 (a side wall along a caseloading direction A). This opening 104 is structured to be openable andcloseable by a door 106 which slides along the loading direction (forexamples, refer to Japanese Patent Application Laid-Open (JP-A) Nos.11-297032, 11-213615, 11-242871 and 2000-331403).

However, with this position of the opening aperture 104, it is necessarythat a drive device side operation member turns a leader pin 108 aroundfrom a direction sideward of the case 102 when drawing out the leaderpin 108. The leader pin 108 is a leader member attached at an endportion of a magnetic tape T, which is the recording tape. Therefore, aspace for this turning around by the operation member must be conservedat the drive device. Moreover, a structure for the turning around by theoperation member is complicated, and inevitably leads to an increase insize of the drive device. In addition, another aspect to be consideredis that a drawing-out path of the magnetic tape T to a winding reel 110becomes long.

Alternatively, in a recording tape cartridge 112 shown in FIG. 8, anopening 116 is formed in a front face wall 114A of a case 114 (a forwardwall which faces in case loading direction A). This opening 116 isstructured to be openable and closeable by a swivel-type door 118, whichopens and closes by rotation about a shaft (for examples, refer to JP-A9-039832 and the specification of U.S. Pat. No. 5,332,173).

In this recording tape cartridge 112, because the opening 116 is formedin the front face wall 114A, there is no requirement for a drive deviceside operation member to turn the leader member around from a sidewarddirection when drawing out a magnetic tape T. However, the door 118opens outward by a large amount. Therefore, it is necessary to conservespace at the drive device side such that opening and closing operationsof the door 118 are not impeded. As a result, the drive device becomeslarger.

Further, in a recording tape cartridge 120 shown in FIG. 9, an opening124 is formed by cutting away a corner portion of a case 122. Theopening 124 is structured to be opened and closed directly by a leaderblock 126, which is a leader member connected to an end portion of amagnetic tape T (for examples, refer to Japanese Patent ApplicationPublication (JP-B) Nos. 61-61470 and 63-53633).

If the leader block 126 functioned only as a door for closing theopening 124, then the occurrence of damage, soiling or the like at theleader block 126 would not be a problem. However, the leader block 126is a structure which is drawn out as is by an operation member andfitted into a hub 130 of a drive device side winding reel 128.Therefore, when damage or soiling occurs at the leader block 126, theleader block 126 may not fit well with the hub 130, and this may have adeleterious effect on running of the magnetic tape T. Moreover, theleader block 126 structures a portion of a winding surface onto whichthe magnetic tape T is wound. Therefore, there is a risk that, as aresult of the aforementioned damage or soiling, data recorded on themagnetic tape T may be damaged or an unrecordable region may be causedat the magnetic tape T.

In addition, the leader block 126 is anchored only at peripheralportions of the opening 124. Therefore, there is a risk that the leaderblock 126 may fall out if the case 122 is dropped. Moreover, because theleader block 126 is larger in size than a leader pin, there are manymore constraints on the form of the case 122.

SUMMARY OF THE INVENTION

In consideration of the circumstances described above, an object of thepresent invention is to provide a recording tape cartridge in which acovering member, which is capable of reducing size of a space foraccommodation thereof at a drive device, can open and close an openingaperture of a structure which is capable of minimizing length of adrawing-out path of a recording tape, without interfering with a reeland a leader member, and with which drive device side opening means,which operates the covering member to open and close the openingaperture, can be provided with a simple construction.

In order to achieve the object described above, according to a firstaspect of the present invention, a tape cartridge which is insertable ata tape drive, the tape drive being provided with an opening member whichis operably engageable with the tape cartridge at a time of insertion ofthe tape cartridge and carrying out at least one of reading and writingof data, the tape cartridge includes: a case which includes a front wallportion facing in a direction of insertion of the cartridge, a side wallportion substantially parallel to the cartridge insertion direction, andan angled wall portion connecting the front wall portion and the sidewall portion, and angled relative to the cartridge insertion direction;a tape access opening provided at the angled wall portion of the case; acovering member which is reciprocally moveable along a circular arc-formmovement path between a closed position for closing the tape accessopening and an open position for opening the tape access opening; anoperation portion provided at the covering member, the operation portionbeing capable of moving the covering member in an open positiondirection when engaged with the opening member of the tape drive by anoperation of insertion of the tape cartridge; a window portion providedat the side wall portion of the case, which window portion allowsrelative engagement of the opening member of the tape drive with theoperation member at the time of insertion of the tape cartridge; and aslide guidance portion disposed along the circular arc-form movementpath and at least one of line-contacting and surface-contacting thecovering member.

According to another aspect of the present invention, in a tape drivefor carrying out at least one of reading and writing of data at a tapecartridge that includes: a case which includes a front wall portionfacing in a direction of insertion of the cartridge, a side wall portionsubstantially parallel to the cartridge insertion direction, and anangled wall portion connecting the front wall portion and the side wallportion and angled relative to the cartridge insertion direction; a tapeaccess opening provided at the angled wall portion of the case; acovering member which is reciprocally moveable along a circular arc-formmovement path between a closed position for closing the tape accessopening and an open position for opening the tape access opening; anoperation portion provided at the covering member, the operation portionbeing capable of moving the covering member in an open positiondirection when engaged with the tape drive by an operation of insertionof the tape cartridge; a window portion provided at the side wallportion of the case, which window portion allows relative engagement ofthe tape drive with the operation member of the covering member at atime of insertion of the tape cartridge; and a slide guidance portiondisposed along the circular arc-form movement path and at least one ofline-contacting and surface-contacting the covering member, the tapedrive includes an opening member which is capable of engaging with theoperating portion of the covering member and moving the covering memberin the open position direction at the time of insertion of the tapecartridge.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing overall structure of a recordingtape cartridge relating to an embodiment of the present invention.

FIG. 2 is an exploded perspective view of the recording tape cartridgerelating to the embodiment of the present invention.

FIG. 3 is a plan view of a lower case which structures the recordingtape cartridge relating to the embodiment of the present invention.

FIG. 4 is a perspective view, viewed with an upper case removed, showinga state in which an opening, which structures the recording tapecartridge relating to the embodiment of the present invention, is closedby a door.

FIG. 5 is a perspective view, viewed with the upper case removed,showing an open state of the opening which structures the recording tapecartridge relating to the embodiment of the present invention.

FIG. 6A is a plan view showing an opening process of the opening of therecording tape cartridge relating to the embodiment of the presentinvention, viewed with the upper case removed, which shows an initialstate of engagement of an engaging protrusion of a drive device with anoperation projection of the door.

FIG. 6B is a plan view showing the same opening process, which shows astate during opening of the opening.

FIG. 6C is a plan view showing the same opening process, which shows astate of complete opening of the opening.

FIG. 7 is a perspective view showing overall structure of a conventionalrecording tape cartridge.

FIG. 8 is a perspective view showing overall structure of anotherconventional recording tape cartridge.

FIG. 9 is a perspective view showing overall structure of yet anotherconventional recording tape cartridge.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

A recording tape cartridge 10 relating to an embodiment of the presentinvention will be explained based on FIGS. 1 to 6C. Firstly, generaloverall structure of the recording tape cartridge 10 will be explained.Then, principal elements of the present invention, an opening 20 and adoor 50 which serves as a covering member for opening and closing theopening 20, will be explained. For the sake of convenience ofexplanation, a loading direction of the recording tape cartridge 10 intoa drive device, which is shown as arrow A, is referred to as a forwarddirection (front side) of the recording tape cartridge 10, and thedirection of an arrow B intersecting arrow A is a rightward direction.

[Overall Structure of Recording Tape Cartridge]

FIG. 1 shows a perspective view of overall structure of the recordingtape cartridge 10. FIG. 2 shows a schematic exploded perspective view ofthe recording tape cartridge 10.

As shown in these drawings, the recording tape cartridge 10 isstructured to rotatably accommodate a single reel 14 in a case 12. Thecase 12 is substantially rectangular in plan view. A magnetic tape T iswound onto the reel 14. The magnetic tape T serves as a recording tapewhich is an information recording/replaying (reading/writing) medium.

The case 12 is structured by matching up and joining two peripheralwalls 16A and 18A of an upper case 16 and a lower case 18 to oneanother. A front-right corner portion of each of the upper case 16 andthe lower case 18, which is a single corner portion at a front end sidein the direction of loading into the drive device, is cut away. Anaccommodation space for the reel 14, onto which the magnetic tape T iswound, is provided inside the case 12. Hence, the cut away cornerportions of the peripheral walls 16A and 18A of the upper case 16 andthe lower case 18 serve as the opening 20 for drawing out the magnetictape T.

A leader pin 22 is connected at a free end of the magnetic tape T thatis drawn out through the opening 20. The leader pin 22 is caught up(engaged) by drawing-out means of the drive device, and subjected to adrawing-out operation. At each of two end portions of the leader pin 22,which protrude beyond width direction end portions of the magnetic tapeT, an annular groove 22A is formed. These annular grooves 22A are caughton to by hooks or the like of the drawing-out means. Consequently, inthis structure, the hooks or the like do not contact and damage themagnetic tape T when the magnetic tape T is drawn out.

At an inner side of the opening 20 of the case 12, a pair of upper andlower pin stands 24 are provided for positioning and retaining theleader pin 22 in the case 12. The pin stands 24 have semi-tubular forms,and both the end portions of the leader pin 22 are held at recessportions 24A of the pin stands 24 in a state in which the leader pin 22is standing thereat. Outer peripheral walls of the pin stands 24 areopen at a magnetic tape T drawing-out side thereof, to form exit/entryapertures through which the leader pin 22 is removed and inserted.

A leaf spring 25 is fixedly disposed in a vicinity of the pin stands 24.The leaf spring 25 engages with upper and lower end portions of theleader pin 22, and holds the leader pin 22 at the pin stands 24. Theleaf spring 25 is structured to resiliently deform appropriately whenthe leader pin 22 is removed or inserted at the pin stands 24, and toallow movements of the leader pin 22.

A gear aperture 26 is formed at a central portion of the lower case 18.The gear aperture 26 is for exposing an unillustrated reel gear of thereel 14 to the outside. The reel gear meshes with a driving gear of thedrive device, and the reel 14 is driven to rotate inside the case 12.Further, the reel 14 is held by free play-restricting walls 28 so as notto rattle about. The free play-restricting walls 28 are providedprojecting at interior surfaces of the upper case 16 and the lower case18, to serve as interior walls partially disposed along a circular pathwhich is coaxial with the gear aperture 26.

A hollow portion 28A is provided continuously with an end portion of thefree play-restricting walls 28 in a vicinity of the opening 20. A holefor regulation of position at an interior is formed in the hollowportion 28A. In addition, a hollow portion 28B is formed continuouslywith the free play-restricting walls 28 at an inner side of a front-leftcorner portion of the case 12. Another hole for regulation of position,which is a long hole, is formed in the hollow portion 28B. The hollowportion 28A and the hollow portion 28B are disposed co-linearly alongthe direction of arrow B.

Except for the end portion at which the hollow portion 28A iscontinuously provided, each of the free play-restricting walls 28 isprovided continuously with the peripheral wall 16A or the peripheralwall 18A of the case 12. Thus, outer sides of the free play-restrictingwalls 28 and the space for disposing the reel 14 are set apart.

[Structure of Opening and of Case at Opening Vicinity]

As described above, the opening 20 is formed by cutting away thefront-right corner portion. Therefore, an opening face thereof (anangled wall portion) faces in the direction of arrow A and in thedirection of arrow B. Consequently, the drawing-out means of the drivedevice can access and chuck the leader pin 22 from the direction ofarrow A, from the direction of arrow B, or from a direction between thedirections of arrow A and arrow B.

As a result, an area in which the pin stands 24 that hold the leader pin22 can be disposed is large, and a range from which the drawing-outmeans of the drive device can chuck the leader pin 22 is wide.Accordingly, a disposition position of the pin stands 24 can bespecified to meet specifications of drive devices that carry outchucking from direction A and drive devices that carry out chucking fromdirection B. Thus, a degree of freedom of design of the drive device isbroadened.

As is also shown in FIG. 3, which is a plan view of the lower case 18, apair of short upper and lower diagonal wall portions 30 is provided at aright corner portion of a front wall 12A of the case 12 (a portion ofthe peripheral walls 16A and 18A whose outer surface faces in thedirection of arrow A). The diagonal wall portions 30 define a front edgeportion of the opening 20. The diagonal wall portions 30 curve to runalong the opening face of the opening 20, and a wall thickness of thediagonal wall portions 30 is thicker than the front wall 12A.

A recess portion 30A is formed at a thickness direction central portionof the diagonal wall portions 30. A distal end of the door 50, which isdescribed later, enters into the recess portion 30A. Further, a pair ofupper and lower screw bosses 32 are provided continuously with an innerside of the front wall 12A in a vicinity of a left end of the diagonalwall portions 30.

A pair of upper and lower offset wall portions 34 is provided at a frontend portion of a right wall 12B of the case 12 (a right side wall of theperipheral walls 16A and 18A along the direction of arrow A). The offsetwall portions 34 are slightly offset to the inside of the case 12(leftward). Front ends of the offset wall portions 34 define a rear edgeof the opening 20.

A pair of upper and lower screw bosses 36 is provided continuously withan inner side of front end portions of the offset wall portions 34.Outer peripheral portions of the screw bosses 36 function as a guide forthe door 50 which is slidable against the door 50 (to prevent rattling).Further, a pair of upper and lower step portions 38 is integrally formedbetween rear end portions of the offset wall portions 34 and the rightwall 12B.

A slit 40 having a predetermined length, which serves as a windowportion communicating between the interior and exterior of the case 12,is formed in the right wall 12B rearward of the offset wall portions 34.The slit 40 is for exposing an operation projection 52 of thebelow-described door 50. The slit 40 is formed by cutting away a lowerportion of the peripheral wall 16A and an upper portion of theperipheral wall 18A, which structure the right wall 12B. By also cuttingaway a lower portion and an upper portion, respectively, of the upperand lower step portions 38, the slit 40 is also opened frontward.

That is, the offset wall portions 34 are provided so as to be offsetinward relative to the right wall 12, such that the slit 40, at whichthe operation projection 52 of the door 50 is operable (engageable) fromfrontward as described below, is not formed continuously (communicating)with the opening 20. A front end of the offset wall portions 34 definesa rear edge of the opening 20, and a rear end of the offset wallportions 34 defines a substantial front edge of the slit 40. Thus, inthis structure, the opening 20 and the slit 40 are formed in the case 12so as to be mutually non-continuous.

The offset wall portions 34, together with the right wall 12B,correspond to a “side wall along a loading direction of the case intothe drive device” of the present invention.

The protrusion portion 42 protrudes from rear end portions of the upperand lower offset wall portions 34, at a side thereof which is oppositeto a side thereof at which the step portions 38 are disposed (that is,inward of the case 12) and is provided to span the whole height of theoffset wall portions 34. A distal surface of the protrusion portion 42is curved to correspond to an outer surface of the later-described door50. In addition, a protrusion portion 44 spanning the whole height isprovided at a location of the free play-restricting walls 28 whichcorresponds to the protrusion portion 42. The protrusion portion 44 iscurved to correspond with an inner face of the door 50, and opposes theprotrusion portion 42.

When the door 50 opens or closes the opening 20, the protrusion portion42 and the protrusion portion 44 are slidable against the door 50 whilesandwiching the door 50. Thus, the protrusion portion 42 and theprotrusion portion 44 are for preventing the ingression of dust into thecase 12, and are for guiding the door 50 (preventing looseness).

A further protrusion portion 46 protrudes inward of the case 12 at aportion of the right wall 12B (the peripheral walls 16A and 18A) thatdefines a rear end of the slit 40. The protrusion portion 46 is also forpreventing the ingression of dust into the case 12 and guiding the door50 (preventing rattling).

A recess portion 48 is formed rearward of the protrusion portion 46 ofthe lower case 18. The recess portion 48 is recessed toward the insideof the case 12 at a portion of the peripheral wall 18A, which does notinclude an upper end of the peripheral wall 18A, and upward from a lowerface of the case 12, and substantially has a three-sided box shape insectional view. The recess portion 48 is also formed in a left wall ofthe case 12. These recess portions 48 serve as, for example, engagingportions for engaging with the drawing-out means of the drive device,with bottom surfaces of the recess portions 48 (surfaces that facedownward) serving as reference surfaces for positioning in the drivedevice. Furthermore, twisting strength of the case 12 is improved byprovision of the recess portions 48.

A portion of the right wall 12B (the peripheral wall 18A) that definesthe recess portion 48 is curved to correspond to the outer surface ofthe door 50. This guide surface 48A serves as a guide for the door 50,and is slideable against the outer surface of the door 50 when theopening 20 is opening or closing (to prevent looseness).

The screw bosses 36, the protrusion portions 42, 44 and 46, and theguide surface 48A described above correspond to “guidance means” of thepresent invention. Of these, the protrusion portions 42 and 46, whichare provided spanning the whole height of the interior of the case 12 atboth sides in the front-rear direction of the slit 40 (the direction ofarrow A), correspond to a “pair of sliding portions” of the presentinvention.

The upper case 16 and the lower case 18 described above are fixed(joined) by unillustrated screws which are screwed from the lower sideinto each of the screw bosses 32 and 36 (joining portions), which arelocated in the vicinities of edge portions of the opening 20.Accordingly, corner portions at both ends of the opening 20, which aredefined by free ends of the diagonal wall portions 30 (the front wall12A) and the offset wall portions 34 (the right wall 12B) and which tendto be severely affected when impacted against a floor or the like by afall, are securely fixed. Thus, even if the case 12 is dropped, thisstructure will not be deformed or buckled by the overall weight of therecording tape cartridge 10, so as to cause mispositioning.

In particular, the upper case 16 and the lower case 18 are fixed withscrews at the screw bosses 36, which are provided continuously with theoffset wall portions 34 located between the opening 20 and the slit 40.As a result, even with the structure being provided with the slit 40 toserve as the window portion in the right wall 12B, dropping strength ofthe case 12 is maintained. The slit 40 may be defined from above andbelow simply by a ceiling plate and floor plate of the case 12. However,as mentioned above, by leaving portions of the peripheral walls 16A and18A above and below to function as ribs, rigidity of the case 12 ismaintained, and the dropping strength is more preferable with thisstructure. Moreover, because the protrusion portions 42, 44 and 46 whichstructure the guidance means each functions as a rib (a reinforcingmember), rigidity of the case 12 is further improved with thisstructure.

A major diameter across the threads of the screws may be, for example,2.0 mm. Thus, an external diameter of the screw bosses 32 and the screwbosses 36 may be 4.0 mm. In place of this fixing with screws,projections may project from the upper case 16 at positionscorresponding to the screw bosses 32 and 36, while fitting holes whichfit with these projections are formed in the lower case 18, and theprojections and fitting holes may be fitted with one another. However,in such a case, it is desirable that the upper case 16 and the lowercase 18 be fixed with screws at locations within radii of 30 mm of thesefitting locations. Further, matching surfaces of the peripheral wall 16Aand the peripheral wall 18A (at both side corner portions of the opening20) may be fixed by welding. However, fixing with screws is morepreferable in consideration of dismantling and recycling.

Plate thicknesses of both the upper case 16 and the lower case 18 areset to 2 mm at the area in which the pin stands 24 are disposed (thevicinity of the opening 20), which is thicker than thicknesses at otherareas thereof. The case 12 (the upper case 16 and the lower case 18) isformed of a polycarbonate (PC) material. The case 12 may be formed ofacrilonitrile butadiene styrene (ABS) or a metal instead of PC.

The purpose of this is to raise the strength of the vicinity of the pinstands 24, which is the location at which the leader pin 22 is held(positioned). Therefore, mispositioning of the leader pin 22, which isthe most important component for functioning of the recording tapecartridge 10 (and which must be accurately engaged by the drawing-outmeans when the recording tape is to be drawn out), subsequent to impactsdue to dropping of the case 12 (the recording tape cartridge 10) or thelike does not occur.

Positions at which the pin stands 24 are disposed are determined suchthat an axial center of the leader pin 22 held thereat is positioned ona first imaginary line (not illustrated), which joins the front and rearedge portions of the opening 20, or further inside the case 12 than thefirst imaginary line. The positions at which the pin stands 24 aredisposed are more preferably determined such that the axial center ofthe leader pin 22 is positioned on a second imaginary line (also notillustrated), which joins axial centers of the screw bosses 32 and thescrew bosses 36, or further inside the case 12 than the second imaginaryline. In the present embodiment, the pin stands 24 are disposed at aposition closer to the screw bosses 32 than to the screw bosses 36.Thus, with this structure, mispositioning of the leader pin 22 due tovibrations of the ceiling plate and the floor plate that accompanydropping of the case 12 or the like can be prevented.

In this case 12, the peripheral wall 16A of the upper case 16 and theperipheral wall 18A of the lower case 18 are set to equal heights. Thus,machining accuracies of portions thereof that match up with one another(accuracies of resin-forming in molds) are at about the same level.Thus, assembly characteristics and dropping impact resistance are madefavorable.

A diagonal angle of the opening face of the opening 20 with respect tothe direction of arrow A (a diagonal angle of the ceiling plate andfloor plate of the case 12 that define the top and bottom of the opening20) is determined in accordance with requirements for distinguishing(identifying) the recording tape cartridge 10 at a library apparatus.That is, the library apparatus accommodates a plurality of the recordingtape cartridge 10 and automatically (i.e., without human intermediation)mounts and removes the recording tape cartridge 10 at the drive device.In a case where there is a plurality of types of the recording tapecartridge 10 to be handled and a plurality of types of drive device, itis necessary to identify a generation, recording capacity or the like ofthe recording tape cartridge 10. The diagonal angle of the opening faceof the opening 20 may be utilized for this identification.

Accordingly, the opening 20 for drawing out of the magnetic tape T,which has been implemented in consideration of strength as describedabove, can also function as an identification portion in a libraryapparatus, based on the diagonal angle of the opening face of theopening 20 (to be specific, the diagonal angle of the ceiling plate andfloor plate that define the top and bottom of the opening 20).Therefore, insufficient strength of the case 12, a deterioration ofdustproofing and complicated mold construction, which are concerns in asituation in which the opening 20 and the identification portion areprovided separately (for example, a case in which one or a plurality ofthrough-holes formed in the case 12 serve as an identification portion),can be prevented.

[Door Structure]

As shown in FIGS. 4 and 5, which are viewed with the reel 14, the uppercase 16 and the like removed, the opening 20 is opened and closed by thedoor 50, which serves as a covering member. The door 50 is formed in acircular arc form in plan view, which is curved in a plate thicknessdirection along a predetermined circular circumference, with a platewidth (height) of the door 50 set to be substantially the same as anopening height of the opening 20, and a plate length thereof beingsignificantly greater than an opening width of the opening 20.

Specifically, in this structure, in a state in which the door 50 hasentered into the recess portion 30A of the diagonal wall portions 30 (aclosed position), the door 50 closes the opening 20 (see FIG. 6A). Thedoor 50 opens the opening 20 by moving (rotating) substantially rearwardalong the aforementioned circular circumference, (see FIG. 6B). When anouter peripheral surface of a distal end vicinity of the door 50 reachesa vicinity of the screw bosses 36, the opening 20 is completely opened(an open position; see FIG. 6C). When the opening 20 is open, the door50 closes the opening 20 by rotating substantially in the oppositedirection. In the closed state of the opening 20, the door 50 abutsagainst at least one of the screw bosses 36, the protrusion portion 42and the protrusion portion 44.

That is, the door 50 is formed to be curved in an arc shapecorresponding to the predetermined circular circumference, which is amovement path of the door 50. In the present embodiment, a position of acenter of rotation of the door 50 in a left-right direction is specifiedto be at a left end vicinity of the case 12, and a position thereof in afront-rear direction is specified to be at a vicinity of the rear end ofthe slit 40. Consequently, the movement path of the door 50 is closestto the right wall 12B of the case 12 in the vicinity of the rear end ofthe slit 40. The rotation center and a turning radius of the door 50 maybe suitably determined in accordance with the positions of the front andrear edge portions of the opening 20 (the diagonal wall portions 30 andthe screw bosses 36). These positions are determined by requirements ofthe drive device, in accordance with the angle of the facing surface ofthe opening 20, which is determined by requirements of a libraryapparatus, and the like.

A rear end portion of a length dimension along the curve of the door 50is determined so as to be located at a rear-right corner portion, whichis rearward of the recess portion 48 of the case 12, in the state inwhich the opening 20 is closed.

Thus, the door 50 is disposed to be slideable against the screw bosses36, the protrusion portions 42, 44 and 46, and the guide surface 48A ofthe case 12, which structure the guidance means, for rotating along thecircular circumference direction to open and close the opening 20.Accordingly, in this structure, the door 50 is guided in the opening orclosing direction of the opening 20, and rattling is suppressed whilethe door 50 slides against at least a portion of the screw bosses 36,the protrusion portions 42, 44 and 46, and the guide surface 48A (andthe outer surface of the free play-restricting walls 28) when the door50 is opening or closing the opening 20.

At an outer peripheral surface of the door 50, slightly forward from alength direction central portion thereof, the operation projection 52projects along a diametric direction of the door 50, to serve as anoperation portion. The operation projection 52 is exposed to the outsideof the case 12 through the slit 40. When the opening 20 is in the closedstate, the operation projection 52 is positioned to be slightlyseparated from the protrusion portion 42 at the rear end of the offsetwall portions 34, and is operable through the portion of the slit 40that opens frontward at the step portions 38. Dimensions of each portionare determined such that a distal end portion of the operationprojection 52 does not protrude further than the outer surface of theright wall 12B (an exterior profile of the case 12) in this state (seeFIGS. 4 and 6A).

When the opening 20 is in the opened state, the operation projection 52is positioned to be slightly separated from the protrusion portion 46 atthe rear edge of the slit 40. The dimensions of each portion aredetermined such that a length direction of the operation projection 52is substantially perpendicular to the right wall 12B of the case 12 (thedirection of arrow A) in this state.

When the case 12 undergoes an operation of loading the case 12 into thedrive device, the engaging protrusion 60 (see FIGS. 6A to 6C), which isfixedly provided in the drive device, advances into the slit 40 througha frontward opening portion thereof, and engages with the operationprojection 52. At this time, the operation projection movessubstantially rearward along the aforementioned circular circumference,and the operation projection 52 moves the door 50 in the openingdirection of the opening 20 (that is, in the circular circumferencedirection).

Consequently, a force acts on the operation projection 52 along thefront-rear direction (the direction of arrow A) from the engagingprotrusion 60. In addition to a rotation force in the circumferentialdirection of the door 50, a force component in the diametric directionthereof (a force component whose direction and magnitude change in theprocess of opening the opening 20) acts on the door 50. However, becausethe door 50 is guided by the screw bosses 36, the protrusion portions42, 44 and 46, and the guide surface 48A as described above (loosenessis restricted), the door 50 can be moved smoothly by the above-describedoperation on the operation projection 52.

Although this operation projection 52 communicates between the interiorand exterior of the case 12 via the slit for exposure, the slit 40 isalways substantially closed by the door 50, which spans substantiallythe whole height of the interior of the case 12, and by the protrusionportion 42 and protrusion portion 46 which guide the door 50. Inaddition, a labyrinthine structure is formed between the slit 40 and theaccommodation space for the reel 14 by the free play-restricting walls28 which serve as inner walls and the protrusion portion 44 which guidesthe door 50. Accordingly, adherence of dust and the like to the magnetictape T wound onto the reel 14 is prevented.

A spring-holding portion 54 protrudes along the diametric direction ofthe door 50 from an interior peripheral portion at a rear end vicinityof the door 50. One end portion of a coil spring 56, which serves asurging means (an urging element), is engaged with a spring-engagingportion 55, which is provided inside the case 12 at a vicinity of therecess portion 48. Another end portion of the coil spring 56 is engagedand held at the spring-holding portion 54. Accordingly, in thisstructure, the door 50 is urged in a direction to close the opening 20by urging force of the coil spring 56, and the door 50 continuouslycloses the opening 20.

The coil spring 56 has a length that reaches as far as the rear-rightcorner portion of the case 12 in the state in which the door 50 opensthe opening 20 as described above. Thus, the coil spring 56 is disposedso as to effectively use a space between the free play-restricting walls28 and the peripheral walls 16A and 18A at the rear-right cornerportion.

The door 50 described hereinabove is formed of, for example, apolyoxymethylene (POM) resin, which has a low coefficient of frictionand has excellent abrasion resistance with respect to the case 12constituted of PC. The operation projection 52, the spring-holdingportion 54 and the like may be structured as separate bodies (ofdifferent materials). Thus, because operation of the door 50 can becarried out smoothly, it is preferable if clearances between endsurfaces at the top and bottom of the door 50 and the ceiling plate andfloor plate of the 12 are set to the order of 0.05 mm to 0.2 mm each.

Next, operation of the present embodiment will be described.

In the recording tape cartridge 10 having the structure described above,the opening 20 is closed by the door 50 when the recording tapecartridge 10 is not in use (during storage, during transportation, andthe like). Specifically, a distal end portion (front end portion) of thedoor 50 is entered into the recess portion 30A of the diagonal wallportions 30 by the urging force (force component F1) of the coil spring56. At the same time, an intermediate portion outer peripheral surfaceof the door 50 abuts against the outer peripheral surface of the screwbosses 36 to close the opening 20.

Further, the slit 40 is substantially closed by the door 50 and theprotrusion portions 42 and 46 which are provided at both sides of theslit 40 to be slideable against the door 50. Moreover, a labyrinthinestructure is formed in the case 12 by the free play-restricting walls 28and the protrusion portion 44. Thus, ingression of dust into theaccommodation space of the reel 14 is prevented.

Hence, at times of non-use of the recording tape cartridge 10, theadherence of dust and the like to the magnetic tape T that is wound ontothe reel 14 accommodated in the case 12 is prevented.

In contrast, when the magnetic tape T is to be used, the recording tapecartridge 10 is loaded into the bucket 60 of the drive device along thedirection of arrow A. In accordance with this loading, as shown in FIG.6A, the engaging protrusion 60, which serves as the opening member(opening means) of the drive device, advances into the slit 40 whichopens frontward at the step portions 38, and engages with the operationprojection 52 of the door 50.

As the recording tape cartridge 10 (the case 12) is pushed in further,the urging force of the coil spring 56 is opposed by a force of pushingin and, as shown in FIG. 6B, the engaging protrusion 60 moves theoperation projection 52 rearward (that is, relatively rearward withrespect to the case 12 which is being loaded in the direction of arrowA).

Thus, the door 50 from which the operation projection 52 protrudes isguided by the screw bosses 36, the protrusion portions 42, 44 and 46,and the guide surface 48A. At the same time, the door 50 rotatesclockwise, in plan view, along the direction of curvature thereof. Thatis, the door 50 moves substantially rearward so as to swing at the outerside of the reel 14 and the pin stands 24 without significantlydeviating from the movement path along the shape of the curvature, andthe door 50 opens the opening 20.

Then, when the case 12 (the recording tape cartridge 10) has been loadedto a predetermined depth in the drive device, the opening 20 iscompletely opened, as shown in FIG. 6C. In this state, the recordingtape cartridge 10 is positioned in the drive device, and furtherrotation (substantially rearward movement) of the door 50 is suppressed.

In this state, the drawing-out means of the drive device advances intothe case 12 through the opened opening 20, and the drawing-out meanstakes out the leader pin 22, which has been positioned and accommodatedat the pin stands 24, and accommodates the leader pin 22 at the windingreel. Then, the winding reel and the reel 14 are driven to rotate at thesame time, and the magnetic tape T is wound around the winding reelwhile being sequentially drawn out from the case 12. Informationrecording/replaying is carried out on the magnetic tape T by therecording/replaying head or the like which is disposed along thepredetermined tape path.

Subsequently, the magnetic tape T is wound back to the reel 14 again,and the recording tape cartridge 10 is ejected from the drive device. Atthe time of ejection, a positioning state of the recording tapecartridge 10 is released, and the recording tape cartridge 10 is movedin a direction opposite to the direction of arrow A by the urging forceof the coil spring 56 and/or by an unillustrated ejection mechanism.

In accordance with this ejection operation, the door 50 is guided by thescrew bosses 36, the protrusion portions 42, 44 and 46, and the guidesurface 48A, while being rotated in the closing direction of the opening20 by the urging force of the coil spring 56. The distal end portion ofthe door 50 enters into the recess portion 30A of the diagonal wallportions 30, and the door 50 returns to the initial state in which theopening 20 is completely closed.

Here, because the opening 20 is formed by cutting away the loading sidecorner portion of the rectangular case 12, the opening face of theopening 20 faces in the direction of arrow A and in the direction ofarrow B (the facing angle is diagonal with respect to the direction ofarrow A). This means that the drawing-out means of the drive device cangain access to the leader pin 22 from a front face side which faces thecase 12 in the direction of arrow A, and it is not required that thedrawing-out means gain access from a side that is outside of the arrow Bside peripheral walls (side walls) 16A and 18A (i.e., from an arrow Bside).

Consequently, in this drive device, a path for drawing out the magnetictape T can be made as short as possible, and the drawing-out means doesnot require a drive mechanism for turning the magnetic tape T aroundfrom the arrow B side of the case 12. Thus, a reduction in size and costreductions can be expected.

Further, the door 50, which is curvedly formed in the circular arcshape, is rotated to open and close the opening 20 by swinging around anouter side of the reel 14 and the pin stands 24 (and the leader pin 22)without deviating from the movement path along the shape of thecurvature. Therefore, the door 50 will not protrude beyond an externalprofile region of the case 12 during opening and closing of the opening20.

Consequently, a space for accommodation of the recording tape cartridge10 in the drive device is small, and the movement path of the door 50does not interfere with the pin stands 24 (the leader pin 22), the reel14 and the like in the case 12.

Further yet, it is sufficient that the engaging protrusion 60 of thedrive device be fixedly disposed to be engageable with the operationprojection 52 of the door 50 simply by advancing into the slit 40 fromfrontward thereof. Thus, construction is simple. Further again, becausethe door 50 closes the opening 20 due to the urging force of the coilspring 56, a drive device side mechanism for driving the door 50 in thedirection of closing the opening 20 is not required. Thus, constructionof the opening means (opening member) of the drive device is made moresimple.

Accordingly, with the recording tape cartridge 10 according to thepresent embodiment, the door 50, which can make a space foraccommodating the recording tape cartridge 10 at the drive devicesmaller, can open and close the opening 20, whose structure can minimizelength of the drawing-out path of the magnetic tape T, without the door50 interfering with the reel 14 and the leader pin 22. Moreover, theengaging protrusion 60, which serves as the opening means (openingmember) for operating the door 50 to open and close the opening 20, canbe given a simple structure.

Thus, the screw bosses 36, the protrusion portions 42 and 46, and theguide surface 48A, which are provided (continuously provided) protrudingtoward the interior at an inner face of the right wall 12B of the case12 (and the offset wall portions 34), and the protrusion portion 44,which is provide protruding toward the exterior at an outer face of thefree play-restricting walls 28, structure the guidance means whichguides the door 50 in the opening and closing directions of the opening20. Therefore, there is no need to provide a reduced thickness portionsuch as a cam channel in the case 12. Therefore, rigidity of the case 12is high, and the dropping strength can be assured. In particular, theprotrusion portions 42, 44 and 46, which are provided integrally at theoffset wall portions 34, the free play-restricting walls 28 and theright wall 12B, respectively, also respectively function as ribs(reinforcing members). Therefore, the rigidity of the case 12 is evenfurther improved.

Moreover, as described above, the protrusion portions 42 and 46 thatstructure the guidance means have a dustproofing function to prevent theingression of dust and the like into the case 12. Therefore, there is noneed to provide dustproofing members (walls and the like) separatelyfrom the guidance means. Thus, construction is more simple, and spacesavings can be expected. Furthermore, the free play-restricting walls 28and the protrusion portion 44 provided at the free play-restrictingwalls 28 form a labyrinthine structure, and thus have a dustproofingfunction. Consequently, dustproofing is improved with a simpleconstruction.

Because the movement path of the door 50 as described above is acircular circumference (a curvilinear shape), the corner portion of thecase 12 can be greatly cut away, and the opening 20 can be formed to belarge. That is, in a case in which, for example, a flat plate-formcovering member is inclined relative to the direction of arrow A, thiscovering member will be accommodated in an exterior profile region ofthe case 12. In this situation, an operation area that is required forchanging the attitude of the covering member by linear displacement orrotary displacement to open and close the opening 20 will be greater,and the opening 20 will have to be made smaller (the cutaway portion ofthe corner portion of the case 12 that forms the opening 20 will have tobe made smaller) such that the operation of the covering member does notinterfere with the leader pin 22, the reel 14 and the like. However,with the recording tape cartridge 10 relating to the present embodiment,because the door 50 which opens and closes the opening 20 by turning onthe predetermined circular arc without deviating therefrom as describedabove is provided, an increase in size of the opening 20 can be enabled.

In particular, a center of rotation of the door 50 for opening andclosing the opening 20, whose opening face is diagonal with respect tothe direction of arrow A, can be determined independently of theposition of an axial center of the reel 14. Therefore, the angle ofinclination of the opening face of the opening 20 relative to thedirection of arrow A, the size of the opening 20 (a separation betweenfront and rear edge portions thereof, and the like can be freelyspecified. Thus, the door 50 can be provided for opening and closing theopening 20, with the opening 20 having dimensions and shape freelyselected in accordance with requirements of the drive device and thelike. That is, with the structure in which the door 50 is provided, adegree of freedom of design of the opening 20 (and thus the recordingtape cartridge 10) is improved.

Further, when the length of the path for drawing out the magnetic tape Tis minimized as described above, a running path of the magnetic tape Twill inevitably be shortened too. As a result, contact friction of themagnetic tape T with tape guides (for example, rotatably supportedrollers and the like) can be reduced.

Furthermore, the opening 20 is formed by cutting away the corner portionof the case 12, and faces in the direction of arrow A and in thedirection of arrow B. Thus, a range of directions of access to theleader pin 22 by the drawing-out means (by hooks thereof or the like) iswidened. Therefore, positions at which the leader pin 22 can be disposedin the case 12 are broadened. Therefore, given that the operation pathof the door 50 as described above must not interfere with positions atwhich the leader pin 22 can be disposed in practice, a degree of freedomof design of the drive device is improved.

Further again, because the door 50 is a separate member from the leaderpin 22 that is drawn out from the case 12, in this structure the door 50cannot be taken out from the case 12 in an assembled state. Thus, thedoor 50 will not be removed from the case 12 by an impact when therecording tape cartridge 10 is dropped or the like. Moreover, the leaderpin 22 is accommodated in the case 12 in a firmly shut state when theopening 20 has been closed by the door 50 at a time of non-use. Thus,the leader pin 22 is less likely to become damaged or soiled.Consequently, drawing out and running the magnetic tape T at the drivedevice will not affect the drive device, and the magnetic tape T itselfwill not suffer from damage.

Still further, a structure in which a magnetic tape T is employed as arecording tape is used in the embodiment described above. However, thepresent invention is not limited thus. It is sufficient that therecording tape is one of long tape-form information recording/replayingmedia which can record information and replay information that has beenrecorded. Of course, the recording tape cartridge relating to thepresent invention can be applied to recording tape of any kind ofrecording/replaying system.

As is explained above, a recording tape cartridge relating to thepresent invention has excellent effects in that a covering member, whichcan reduce size of an accommodation space of the recording tapecartridge in a drive device, can open and close an opening aperture,which has a structure which can minimize length of a drawing-out path ofa recording tape, without interfering with a reel and a leader member,and a drive device side opening means which operates the covering memberto open and close the opening aperture can have a simple structure.

1. A tape cartridge which is insertable at a tape drive, the tape drivebeing provided with an opening member which is operably engageable withthe tape cartridge at a time of insertion of the tape cartridge andcarrying out at least one of reading and writing of data, the tapecartridge comprising: a case which includes a front wall portion facingin a direction of insertion of the cartridge, a side wall portionsubstantially parallel to the cartridge insertion direction, and anangled wall portion connecting the front wall portion and the side wallportion, and angled relative to the cartridge insertion direction; atape access opening provided at the angled wall portion of the case; acovering member which is reciprocally moveable along a circular arc-formmovement path between a closed position for closing the tape accessopening and an open position for opening the tape access opening; anoperation portion provided at the covering member, the operation portionbeing capable of moving the covering member in an open positiondirection when engaged with the opening member of the tape drive by anoperation of insertion of the tape cartridge; a window portion providedat the side wall portion of the case, which window portion allowsrelative engagement of the opening member of the tape drive with theoperation member at the time of insertion of the tape cartridge; and aslide guidance portion disposed along the circular arc-form movementpath and at least one of line-contacting and surface-contacting thecovering member.
 2. The tape cartridge of claim 1, further comprising areel around which a tape is wound, the reel being accommodated in thecase such that the tape can be drawn out through the tape accessopening.
 3. The tape cartridge of claim 2, further comprising apartition wall portion disposed between the reel and the circulararc-form movement path.
 4. The tape cartridge of claim 3, wherein theslide guidance portion comprises at least one protrusion portion formedat the partition wall portion and at least one protrusion portion formedat the side wall portion of the case.
 5. The tape cartridge of claim 1,wherein the window portion comprises a long, narrow slit provided at theside wall portion of the case and extending along the cartridgeinsertion direction.
 6. The tape cartridge of claim 1, wherein thewindow portion comprises structure such that the window portion does notphysically interfere with the opening member of the tape drive and theoperation member at the time of insertion of the tape cartridge.
 7. Thetape cartridge of claim 1, further comprising a wall portion forreinforcement between the window portion and the tape access opening,which makes the window portion and the tape access openingnon-continuous with one another.
 8. The tape cartridge of claim 7,wherein the slide guidance portion comprises a portion of the wallportion for reinforcement and a protrusion portion formed at the sidewall portion of the case.
 9. The tape cartridge of claim 1, wherein thecase appears substantially rectangular in plan view.
 10. The tapecartridge of claim 1, wherein the case is formed of a resin, and thecovering member is formed of an abrasion-resistant resin which isdifferent from the resin of the case.
 11. The tape cartridge of claim 1,further comprising an urging element which continuously urges thecovering member in a closed position direction.
 12. The tape cartridgeof claim 11, wherein the case comprises an upper case and a lower casewhich structure the case.
 13. The tape cartridge of claim 12, furthercomprising a plurality of joining portions for joining the upper caseand the lower case.
 14. The tape cartridge of claim 13, furthercomprising a leader member attached to a tape end, wherein the leadermember is detachably held at a position on or at an inner side of a linefrom one to another of joining portions that are located at vicinitiesof end portions, in plan view, of the tape access opening.
 15. The tapecartridge of claim 14, wherein the leader member comprises a leader pin,and the tape cartridge further comprises a holding structure whichdetachably holds the leader pin at each side in a longitudinal directionof the leader pin.
 16. A tape drive for carrying out at least one ofreading and writing of data at a tape cartridge that includes: a casewhich includes a front wall portion facing in a direction of insertionof the cartridge, a side wall portion substantially parallel to thecartridge insertion direction, and an angled wall portion connecting thefront wall portion and the side wall portion and angled relative to thecartridge insertion direction; a tape access opening provided at theangled wall portion of the case; a covering member which is reciprocallymoveable along a circular arc-form movement path between a closedposition for closing the tape access opening and an open position foropening the tape access opening; an operation portion provided at thecovering member, the operation portion being capable of moving thecovering member in an open position direction when engaged with the tapedrive by an operation of insertion of the tape cartridge; a windowportion provided at the side wall portion of the case, which windowportion allows relative engagement of the tape drive with the operationmember of the covering member at a time of insertion of the tapecartridge; and a slide guidance portion disposed along the circulararc-form movement path and at least one of line-contacting andsurface-contacting the covering member, wherein the tape drive comprisesan opening member which is capable of engaging with the operatingportion of the covering member and moving the covering member in theopen position direction at the time of insertion of the tape cartridge.17. The tape drive of claim 16, wherein the opening member projects in adirection intersecting the tape cartridge insertion direction.
 18. Thetape drive of claim 16, wherein the opening member is stationary in thetape drive.
 19. The tape drive of claim 16, wherein the opening memberadvances into the tape cartridge at the time of insertion of the tapecartridge.
 20. The tape drive of claim 19, wherein the opening memberadvances through the window portion of the tape cartridge at the time ofinsertion of the tape cartridge.